А) 0
б) 4 1/4
в) 2 3/4
г)5 3/5
Приветствую!
<span>1)2x²-7x-15=0
</span>D<span> = </span>b2<span> - 4 * </span>a<span> * </span>c<span> = -7.0</span>2<span> - 4 * 2.0 * -15.0 = 169
</span>x1 = (-b + D1/2)/2a = (--7.0 + 169.01/2)/(2*2.0) = 5.0x2 = (-b - D1/2)/2a = (--7.0 - 169.01/2)/(2*2.0) = -1.5
2)<span>5x-3\3=3-10x+2\9
<span>5*x - 1 = 3 - 10*x + 2/9
х=38/135
х=0,2(814)</span></span>
Sin a = h/c
h=c*sin a
h= 3*7/9=7/3
S=(9+99)/2*7/3=54*7/3=126
Ответ 126